Low air pressure test device

The invention relates to a low air pressure test device which is used in a space environment simulation system. The low air pressure test device comprises a vacuum tank, an air pumping system, an air inflation system, a pressure measuring system and a control system, wherein the air pumping system comprises two air pumping pipelines, a first pneumatic valve and an electric pressure regulating valve are in tandem connection to a first air pumping pipeline, and second pneumatic valves and a molecular pump are in tandem connection to a second air pumping pipeline; one end of the first air pumping pipeline and one end of the second air pumping pipeline both communicate with the vacuum tank; the other end of the first air pumping pipeline and the other end of the second air pumping pipeline are converged in a main pipeline; a dry type screw pump is connected to the main pipeline. The pressure measuring system comprises an absolute pressure transmitter and a full measuring range vacuum gauge which are connected with the vacuum tank; the air inflation system comprises a mass flow meter and a magnetic valve; the air pumping system, the pressure measuring system and the air inflation system are all connected with the control system. According to the low air pressure test device provided by the invention, an air pumping rate and an air inflation rate can be controlled at the same time; the pressure can be stabilized in the range of pressure required by tests.